Buggy code:
root . add ( line ) ; final double value = ( ( double ) ( i * ( gradDuration ) ) ) ; final String text = formatter . format ( value ) ; final Label label = new Label ( text ) ; label . setLabelAlignment ( RIGHT ) ; label . setForegroundColor ( SWTResourceManager . getColor ( COLOR_WIDGET_FOREGROUND ) ) ; label . setFont ( SWTResourceManager . getFont ( "Cantarell" , 8 , NORMAL ) ) ; label . setToolTip ( new Label ( text ) ) ; label . setSize ( textWidth , ProportionAxisView . TextHeight ) ; GC gc = new GC ( canvas ) ; gc . setFont ( label . getFont ( ) ) ; int labelWidth = gc . textExtent ( label . getText ( ) ) . x ; if ( labelWidth > ( labelMaxWidth ) ) labelMaxWidth = labelWidth ; root . add ( label , new org . eclipse . draw2d . geometry . Rectangle ( new Point ( ( ( ( mainLineXPosition ) - ( ProportionAxisView . TextPositionOffset ) ) - ( textWidth ) ) , ( ( ( ( axisHeight ) - ( ( int ) ( i * ( gradHeight ) ) ) ) + ( ProportionAxisView . TextHeight ) ) - ( ProportionAxisView . Border ) ) ) , new Point ( new Point ( ( ( mainLineXPosition ) - ( ProportionAxisView . TextPositionOffset ) ) , ( ( ( axisHeight ) - ( ( int ) ( i * ( gradHeight ) ) ) ) - ( ProportionAxisView . Border ) ) ) ) ) ) ; for ( int j = 1 ; j < ( ProportionAxisView . NumberOfSubGraduation ) ; j ++ ) { final PolylineConnection line2 = new PolylineConnection ( ) ; if ( ( ( ( ( axisHeight ) - ( ( int ) ( i * ( gradHeight ) ) ) ) - ( ProportionAxisView . Border ) ) + ( ( int ) ( ( j * ( gradHeight ) ) // ( ProportionAxisView . NumberOfSubGraduation ) ) ) ) > ( ( root . getSize ( ) . height ( ) ) - ( ProportionAxisView . Border ) ) ) break ; line2 . setForegroundColor ( SWTResourceManager . getColor ( COLOR_WIDGET_FOREGROUND ) ) ; line2 . setLineWidth ( 1 ) ; line2 . setEndpoints ( new Point ( mainLineXPosition , ( ( ( axisHeight ) - ( ( int ) ( i * ( gradHeight ) ) ) ) + ( ( int ) ( ( j * ( gradHeight ) ) // ( ProportionAxisView . NumberOfSubGraduation ) ) ) ) ) , new Point ( new Point ( ( ( mainLineXPosition ) + ( ProportionAxisView . MiniGradWidth ) ) , ( ( ( axisHeight ) - ( ( int ) ( i * ( gradHeight ) ) ) ) + ( ( int ) ( ( j * ( gradHeight ) ) // ( ProportionAxisView . NumberOfSubGraduation ) ) ) ) ) ) ) ; root . add ( line2 ) ; } } int yPositionOfLastGraduation = ( ( int ) ( ( ( int ) ( gradNumber ) ) * ( gradHeight ) ) ) ; if ( ( drawingHeight ) > yPositionOfLastGraduation ) { int j = 0 ; while ( ( yPositionOfLastGraduation + ( ( int ) ( ( j * ( gradHeight ) ) // ( ProportionAxisView . NumberOfSubGraduation ) ) ) ) < ( drawingHeight ) ) { final PolylineConnection line2 = new PolylineConnection ( ) ; line2 . setForegroundColor ( SWTResourceManager . getColor ( COLOR_WIDGET_FOREGROUND ) ) ; line2 . setLineWidth ( 1 ) ; line2 . setEndpoints ( new Point ( mainLineXPosition , ( ( ( int ) ( axisHeight ) ) - ( yPositionOfLastGraduation + ( ( int ) ( ( j * ( gradHeight ) ) // ( ProportionAxisView . NumberOfSubGraduation ) ) ) ) ) ) , new Point ( new Point ( ( ( mainLineXPosition ) + ( ProportionAxisView . MiniGradWidth ) ) , ( ( axisHeight ) - ( yPositionOfLastGraduation + ( ( int ) ( ( j * ( gradHeight ) ) // ( ProportionAxisView . NumberOfSubGraduation ) ) ) ) ) ) ) ) ; root . add ( line2 ) ; j ++ ; } } String unit = ocelotlView . getOcelotlCore ( ) . getUnit ( ocelotlView . getOcelotlCore ( ) . getMicromodelTypes ( ) . getSelectedOperatorResource ( ) . getUnit ( ) ) ; final Label label = new Label ( unit ) ; label . setLabelAlignment ( RIGHT ) ; label . setForegroundColor ( SWTResourceManager . getColor ( COLOR_WIDGET_FOREGROUND ) ) ; <START_BUG> label . setFont ( SWTResourceManager . getFont ( "Cantarell" , 6 , NORMAL ) ) ; <END_BUG> label . setToolTip ( new Label ( unit ) ) ; label . setSize ( textWidth , ProportionAxisView . TextHeight ) ; GC gc = new GC ( canvas ) ; gc . setFont ( label . getFont ( ) ) ; int labelWidth = gc . textExtent ( label . getText ( ) ) . x ; if ( labelWidth > ( labelMaxWidth ) ) labelMaxWidth = labelWidth ; root . add ( label , new org . eclipse . draw2d . geometry . Rectangle ( new Point ( 0 , 0 ) , new Point ( ( ( mainLineXPosition ) - ( ProportionAxisView . TextPositionOffset ) ) , ProportionAxisView . TextHeight ) ) ) ; } public void drawMainLine ( ) { } public void computeMeasurements ( ) { } protected void resizeAxis ( ) { } @ Override public void initDiagram ( ) { } @ Override public void resizeDiagram ( ) { } @ Override public void select ( int y0 , int y1 , boolean active ) { } @ Override public void unselect ( ) { } }

Fix:
label . setFont ( SWTResourceManager . getFont ( "Cantarell" , 8 , NORMAL ) ) ;